Simulating ceramic-filled vat photopolymerization resins using Monte Carlo ray tracing

Area of Science:

• Materials Science
• Additive Manufacturing
• Photochemistry

Background:

• Vat photopolymerization (VP) of ceramic suspensions faces resolution limitations due to light scattering by ceramic particles.
• Scattered light alters UV intensity distribution, affecting cure depth and width, crucial for part accuracy.

Purpose of the Study:

• To develop a predictive Monte Carlo ray-tracing (MCRT) simulation for light scattering and UV energy absorption in particle-filled resins.
• To accurately model the impact of particle size distribution and refractive index on light propagation within ceramic suspensions for VP.

Main Methods:

• Developed an MCRT simulation incorporating volume-dependent light scattering physics for polydisperse particle sizes.
• Utilized experimentally acquired parameters: refractive index, particle size distribution, light source intensity, and critical exposure.
• Simulated and experimentally validated cure profiles for zinc oxide (ZnO)-filled polyester acrylate resin (refractive index 2.2) at varying ZnO loadings (1-5 vol%).

Main Results:

• The MCRT simulation accurately predicted experimental cure profile shapes.
• Simulated cure depths were within 10% (20 µm) of experimental values.
• Simulated cure widths were within 30% (15 µm) of experimental values.

Conclusions:

• The developed MCRT simulation provides a highly accurate method for predicting photocured profiles in ceramic-loaded resins.
• This predictive capability can enhance resolution and control in vat photopolymerization of composite and ceramic parts.
• The simulation's reliance on experimentally acquired parameters makes it broadly applicable for optimizing VP processes.